Apparatus for maintaining and removing liquid seal for vacuum apparatus



0. MINTON.

APPARATUS FOR MAINTAINING AND REMOVING LIQUID SEAL FOR VACUUM APPARATUS.

APPLICATION FILED MAY 25, I920.

1A23 242, Patented July 18, 1922.

2 SHEETS-SHEET 1.

ATTORNEY 0. MINTON.

APPARATUS FOR MAINTAINING AND REMOVING LIQUID'SEAL FOR VACUUM APPARATUS.

APPLICATION FILED MAY 25, I920. 1,423,%%2. Patented July 18, 1922.

2 SHEETSSHEET 2.

ATTORNEY OGDEN MINTON, OF GREENWICH, CONNECTICUT.

APPARATUS FOR MAINTAINING AND REMOVING LIQUID SEAL FOR VACUUM APPARATUS.

a Application filed. May 25,

To all whom it may concern:

Be it known that I, OGDEN MIN'iON, a citizen of the United States, residing in Greenwich, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Apparatus for Maintaining and Removing Liquid Seal for Vacuum Apparatus, of which the following is a specification taken in connection with the accompanying drawings.

My invention relates to employing two nonmixing liquids of difierent specific gravities, and maintaining, the liquid of heavier specific gravity, in a closed or opened chamber or vessel, by the lighter liquid under pressure. Further, to withdrawing the heav- A ier liquid from the closed or opened'cham-- ber or vessel by reducing the pressureof the lighter liquid.

My invention further relates to maintaining a liquid seal for a vacuum chamber by employing liquids of different specific gravities which will not mix, the liquids into its operative position in the sealing chamber by the other liquid under pressure. My invention further relates to maintaining said liquid seal by the fluid pressure of the other liquid. Further, to removing the sealing liquid from the sealing chamber; by reducing or eliminating the pressure of the other liquid or fluid.

which has My invention further relates to maintaining and withdrawing, as may be desired, the sealing medium in a vacuum drying apparatus in which paper, fabric or other sheet material is dried. My invention further relates to automatically preventing any of the nonsealing fluid working into theliquid seal.

In its more specific adaptation and use In invention relates to a vacuum chamber which is sealed by some liquid sealing medium no deleteriousefi'ect upon or affinity for, the sheet material to be dried in the chamber. This drying is usually done continuously bypassing a continuous web through the liquid seal into the vacuum chamber.

previous Patent 1,147,809 patented July 27,

1915. It also relates to filling and withdrawing a liquid drying bath in an open Specification of Letters Patent.

and forcing one of Patented July 18, 11922. 1920. Serial No. 384,210.

Fig. l is a fragmentary vertical section,

showing my invention applied .to a vacuum drying chamber;

Fig. 2 is a vertical section showing my invention in combination with a different form of sealing chamber of a vacuum drying apparatus;

ig. 3 is a fragmentary detail vertical section of thesimplest form of my invention;

Fig. 4 is a vertical section through a reservoir showing a modification.

In the embodiment oflmy invention shown by way of example 1, Fig. 1, is a fragmen= tary detail view of aportion of a vacuum chamber, such as for example, shown in my copending applications Ser. No. 350,233, Ser. No. 350,234; Ser. No. 350,235 and Ser. No. 350,236, all filed Jan. 8, 1920.

The web 2 of paper, fabric or similar sheet material is fed over the guide roll 3 and into the liquid sealing chamber 4 which normally contains a liquid seal 5 of some medium which has no afiinity for or deleterious effect upon said sheet material. The web passes beneath the guide roll 31 and then up into the vacuum chamber 1 in contact with the guide roll 6 and is dried in said vacuum chamber in any suitable manner, as for example in any one of the different methods shown in my applications above referred to. Usually the liquid seal 5 is mercury, or an amalgam or some similar ma- Eeral having the characteristics above speci There are times when it is desirable to remove the mercury or equivalent sealing medium 5 so that the vacuum chamber may be cleaned or inspected. By my invention I mount a reservoir 7 adjacent to the vacuum chamber and connect it by the pipe 8 to the bottom of the sealing chamber 4. This reservoir is large enough to more than hold all the sealing medium used in the sealing chamber 4. Normally the mercury, or similar liquidsealin medium, will flow into the reservoir 7. When it is desired to use the vacuum chamber 1, valve 9 is closed and valve 10- is opened to permit a fluid or liquid. which will not mix with the liquid of the seal, to flow into the reservoir 7 above the sealing medium 5, which is preferably mercury or equivalent. This second liquid is preferably, though not necessarily, water under pressure. By operating the valve 10 the mercury will be forced up through the pipe 8 into the sealing chamber 4, the vacuum in the chamber 1 drawing the mercury up to about the level 11, which may be observed through the window 12. As soon as the mercury, or equivalent sealing medium, has reached the desired level as for example at 11, the valve 10 is closed and the parts will be substantially as shown in Fig. 1 of the drawing. The mercury is kept at the level indicated at 11 by the water in the reservoir 7 above the mercury. The sealing medium will be permitted to remain in the sealing chamber 4 as long as it is desired to maintain a vacuum in the vacuum chamber 1. If after a long period of use it is desired, to break the vacuum in the vacuum chamber 1, for the purpose of inspection, repair, cleaning or for any other reason, the valve 9 is opened and the mercury or similar medium will flow back into the reservoir 7 and force the water out through the pipe 9, thereby freeing the sealing chamber 4 of the sealing medium 5, whatever that medium may be. It is of course to ice-understood that valve 10, after forcing the mercury or equivalent into the sealing chamber, is normally closed.

Preferably, though not necessarily, I provide means which will automatically prevent any negligence or inattention on the part of the operator flooding the sealing chamber 4 with water or other liquid which ma be used with the mercury or equivalent.

arious forms of automatic control devices may be used. I have for the purpose of illustration shown two such forms, though of course, it is to be understood that my invention is not to be limited'to these forms. I have shown for example in Fig. 1 the bottom of the pipe 8 enlarged to form a T- head 13 having openings 22, 22 through which the mercury passes from the reservoir 7 into the pipe 8. Surrounding the pipe 8, and adapted to move freely upon it, is a float valve 14. When mercury and water are the fluids used I make this valve 14 of iron, which will float uponthe mercury but not upon the water 15. The lower surface of this valve 14 is provided with any suitable material such as leather or rubber 16. Should a careless or inattentive operator open the valve 10 to force the mercury or equivalent into the sealing chamber 4, and leave the parts in this position, the water under pressure will force the mercury into the sealing chamber 4 until such time as the mercury in the vacuum chamber 7 reaches such a low level that the float 14, with its facing 16, will close the openings 22, 22 in the T-head 13. No further mercury will then be forced into the sealing chamber 4, nor will any water or any other liquid which may be used, work into said sealing chamber and serve to injure, mar or ruin the web 2 being dried.

I may in some cases connect up with the float 14, any suitable control device to control the flow of water or other suitable fluid into the reservoir 7. In Fig. 4, I have shown, on a somewhat larger scale, a rod passing through the float 14 and having a stop 18 at one end and also a stop 19. This rod is connected to a lever 20 controlling the valve 21. In this form, in addition tothe float 14 sealing the openings 22, 22 in the T-head 13, the float 14 will operate to close the valve 21 by pulling down the lever 20. The valve- 21 will be automatically opened, so that the valve 10 can again cause the water or similar fluid, to pass into the reservoir 7, by the mercury or equivalent lifting the float 14 until it engages the stop 19, when further movement will cause -the float to slightly rock the lever 20 and open the valve 21. The material of the-float 14 will of course depend upon the specific gravities of the different liquids used.

I have shown in Fig. 2 a different form of vacuum chamber 23 having drying drums 24, 24 and guidev cylinders 25, 25 mounted in the liquid sealing medium of mercury or equivalent 26. The web 2 is fed over the guide roller 3 thence into the sealing chamber 27 around the guide roller 28 and in close contact with the guide cylinder 25 prior to being fed around the drying cylin- 1 ders 24, 24. This particular form of vacuum chamber is covered in a copending application Ser. No. 384,212 filed of even date herewith and will not'be further described in this case.

In this form the pipe 8 is provided with two arms 29, 29 connecting with different portions of the sealing chamber 27.

In the simplest form of my invention I use no float valve or control mechanism to automatically control the passage of water or similar fluid into the reservoir 7. I have shown such a construction in Fig. 3.

It is of course to be understood that in those forms of vacuum chambers employing two separate and distinct sealing chambers, as 1n my copending applications above men.- tioned, a separate reservoir 7 may be used for each sealing chamber, or the two sealing chambers may be connected as shown in Fig. 1

2, so that one reservoir will control the passage of the sealing medium to and from both the sealing chambers.

Having thus described this invention in connection with illustrative embodiments thereof, to the details of which I do not desire to be limited, what is claimed as new and what is desired to secure by Letters Patent is set forth in the appended claims.

What I claim is l. The combination of a vacuum chamber, a sealing chamber sealing the entrance to said vacuum chamber, a reservoir connected with the sealing chamber, a liquid sealing medium, fluid means to force said sealing medium from the reservoir into the sealing chamber and maintain it therein, and means to prevent any of the fluid means getting into the sealing chamber.

2. The combination of a vacuum chamber, a-sealing chamber connected with the vacuum chamber and With a reservoir, a reservoir connected with the sealing chamber, mercury and a nonmixing fluid contained in the reservoir, the mercury adapted to flow into the sealing chamber and become the seal for the vacuum chamber and means to increase or decrease the quantity of the other nonmixing fluid to force the mercury into the sealing chamber or withdraw it therefrom back into the reservoir, and a float in the reservoir adapted to prevent any of the nonmixing fluid getting into the sealing chamber.

OGDEIN MINTON. WVitnesses:

ALAN M. JOHNSON, GLADYs VAN LOAN. 

